This paper presents a study on the expansion of urban Wi-Fi networks and the degree of users’ awareness about their characteristics. It involves an experiment contacted at the area of Serres, a Greek city of around 70,000 inhabitants. The findings revealed that although the number of Wi-Fi networks is quite high, their owners are unaware of their technical settings. As a result many networks remain either unlocked or with WEP encryption while many adjacent networks use the same channel thus reducing their performance.